1. Field of the Invention
This invention relates to a method and apparatus for automatically and successively cramming chip-type electronic components into empty storage means.
2. Description of the Prior Art
An example of a storage casing for surface-mounted-type electronic components is disclosed in Japanese Laid-Open Utility Model Publication No. 141386/1990. The storage casing comprises a plate-like body. The plate-like body has a spiral passageway formed in its interior, an opening formed therein as a continuation of the spiral passageway to communicate with the exterior of the plate-like body, air-intakes communicating with the spiral passageway, and air-outtakes communicating with the spiral passageway. Electronic components are adapted to be crammed into the spiral passageway of the storage casing. The casing having electronic components crammed therein is adapted to be used as a supply source to feed the electronic components to an automatic mounting apparatus for mounting electronic components on printed circuit boards. When the casing having electronic components crammed therein is used as an electronic component supply source, air is intermittently fed into the spiral passageway of the casing through the air-intakes, thereby to discharge the electronic components one by one out of the casing through the opening.
The conventional casing is preferred because it takes the form of a plate-like body, is compact, and has the spiral passageway permitting a plurality electronic components to be received therein. Also, it is preferred because when the casing having electronic components crammed therein is used as an electronic component supply source, the electronic components in the casing can be positively discharged one by one from the opening of the casing only by feeding air into the passageway through the air-intakes. However, when electronic components are crammed into the casing, it is required that cramming of the electronic components into the casing is smoothly and efficiently performed without damaging the electronic components.
It is disclosed in Japanese Laid-Open Patent Publication No. 2395/1986 that a casing comprises a casing body having a spiral groove formed therein, and a cover mounted on the casing body. Where electronic components are to be crammed into the casing, the casing is installed in a vibratory machine. The cramming of the electronic components into the casing is carried out by feeding electronic components into the spiral groove through an opening of the casing while applying vibration to the casing in a manner to cause the vibration to spread in one direction by the vibratory machine. Also, when the electronic components in the casing are to be discharged through the opening of the casing, the vibratory machine applies vibration to the casing in a manner to cause the vibration to extend in the opposite direction, to thereby cause the electronic components to be discharged from the opening. The conventional casing further has a joint member provided at opening thereof. When electronic components are to be crammed into the casing, a tube or chute for feeding components is directly connected to the joint member. The cramming of electronic components into the casing is performed by feeding the electronic components through the tube or chute into the spiral groove and causing the electronic components to be moved toward an inside terminal portion of the spiral groove while applying vibration to the casing by the vibratory machine. As feed means for feeding electronic components through the tube or chute, a vibratory bowl feeder or a multi-feeder is generally employed. In an electronic component cramming system having the vibratory bowl feeder (or the multi-feeder), the tube (or chute to which vibration produced in the bowl feeder spreads is directly connected to the opening of the casing, to which casing vibration produced in the vibratory machine is applied, and there is a difference between the mode of vibration spreading from the vibratory bowl feeder to the chute and the mode of vibration applied to the casing by the vibratory machine. Therefore, the vibrations different in the mode will spread to the connecting portion between the chute and the opening of the casing, resulting in that electronic components fed from the bowl feeder will be jammed without going in the spiral groove of the casing. In addition to this, the both vibrations interfere with each other to apply load to electronic components, resulting in the electronic component and/or the outlet of the casing being harmed.